Search

Suggested Search

Trending Posts

Comments

Fracking, not disposal, behind human-caused earthquakes in western Canada: study

By Bob Weber The Canadian Press

Posted March 29, 2016 12:37 pm

Updated March 30, 2016 8:43 pm

2:18New study links fracking to Western Canada earthquakes

WATCH: New research claims a definitive link between fracking and earthquakes. Experts say it's more proof the controversial process is the cause of a majority of the seismic activity in Western Canada. But as Reid Fiest reports, the findings also say only a very small number of fracking sites actually cause a major tremor.

EDMONTON – New research suggests that hydraulic fracking of oil and gas wells is behind human-caused earthquakes in western Canada.

The study, published Tuesday by a group of top Canadian researchers, concluded that it isn’t injecting wastewater underground that’s causing problems in Alberta and British Columbia — a major step in understanding seismic events in those provinces that have already changed regulations and caused public concern.

“It’s critical that we get to a complete scientific understanding of the issue,” said David Eaton, a University of Calgary geophysicist and a co-author of the study.

Fracking involves pumping high-pressure fluids underground to create tiny cracks in rock and release natural gas or oil held inside. Scientists have previously concluded that oilpatch activity can cause earthquakes by making it easier for faults in underground rock to slip, but they didn’t know whether the Canadian quakes were caused by fracking or by the injection of wastewater back underground.

Eaton and his colleagues began with a database of more than 12,000 fracked and disposal wells drilled between 1985 and 2015. They cross-referenced that with another database of all seismic events over that time.

A complex statistical analysis pinned the blame convincingly on fracking and not disposal, Eaton said.

Story continues below advertisement

“There are more earthquakes in western Canada that are more related to hydraulic fracturing than wastewater injection by a factor of about two.”

Eaton said his findings raise questions about how well the geology of heavily fracked oilfields in Alberta and British Columbia is understood.

Story continues below advertisement

“The occurrences in Canada have come as a surprise — in some cases, to industry — because there was a belief that all the potential faults had been identified,” he said. “One of the things we’re actively researching is to find new and better ways to identify these features.

“We’re looking for the signature of critically stressed faults in new and different ways.”